retrofit stainless steel kettle with copper
I want to add copper to my 30BBl kettle. I was thinking maybe I can braze or weld sheets of copper to the inside of the vessel wall. anyone ever deal with this issue? we want to have the copper for flavor not for helping the yeast. thanks
Last edited by chris reed; 03-02-2005 at 10:15 AM.
We wanted to address what we perceived to be a copper/zinc deficiency by adding copper and zinc plumbing fittings onto an electrical wire and hanging what was dubbed as the 'mojo necklace' into our 50 bbl brew kettle. Our issue was to gain ppb and this did the trick for us.
Make sure you check with your health department to see if you can have copper in contact with a food product.
The FDA in the US says if you are under pH6 in prefermentation and fermentation of a brewery, copper contact is ok according to this: http://www.cfsan.fda.gov/~dms/fc-4.html
Although copper *cannot* contact another beverage product if the pH is below 6.
I have seen this before, but in the form similar to the "mojo" solution. It was a copper plate suspended inside of kettle on the inside of a percolator (it had a large diameter). It was held in place with some stainless bolt "C" clamps. This was many years ago at a brewery I no longer work at.
What exactly are you trying to achieve ? Is it what other respondants have assumed, you want to add zinc / copper to help out underperforming yeast, or something else ?
Here is an other thought about copper vs stainless steel. I read on the internet a couple a days ago about a company telling that beer that did not come in contact with copper could get a off flavour / odour of hydrogen sulfide. I know nothing. Just a reflection. If so most beer should smell like rotten eggs, or?
There once was a brewery that had to produce a beer that was "Fire Brewed". The problem was that they used steam. To solve this, they built a fire box around a copper coil and recirculated the wort through it. This might give you the flavor you are looking for.
Cu2+ Pros & Cons
Copper for flavor? I can understand trace copper for yeast health and foam but at >10 ppm is toxic to yeast and mutagenic in lower amounts. Yeasts like to gather metals; in fact they will often do it to thier deaths (disruption of enzyme systems at low concentrations and fries out the plasmalemma at higher concentrations=muerto). Some 60% of the copper found in healthy yeast is used to build a protein that helps protect yeasts from copper. Furthermore, <1 ppm Cu in final product accelerates all kinds of oxidation, haze and other evils. It can complex with SO4 if present to form not so pleasant CuSO4 precipitate and is also not surprisingly indicated as a culprit in metallic tastes in beer.
I would avoid any retrofits to that nice stainless and let a little copper pipe do the job (e.g., brewing liquor lines, etc.).
In regards to the comment about Cu preventing H2S I have heard this but am unaware of the mechanism. It is supposedly tried and true for certain lager and cider yeast that spew the eggs...
How about tossing some pieces of copper, pipe or whatever, into the kettle loose, or just having a section of piping of copper? Or make your trub dam out of copper. Welding stainless to copper can be a challenge. Keep in mind you don't want to use chlorinated caustic on copper.
Here is a MBAA article that speaks to the mechanism for H2S control with copper.
Is this the flavour benefit you refer to? If not, can you explain what advantage you hope to achieve and cite what source provided the copper flavour benefits idea?